Boris Johnson last night insisted the Iran nuclear deal still ‘has value’ as he held crisis talks with the EU

US President Donald Trump gives speech on plans to withdraw from Iran nuclear deal

And he also pledged to raise “difficult consular cases”, including the plight of jailed British mum Nazanin Zaghari-Ratcliffe.

Mr Johnson spoke to reporters as he and counterparts from Germany and France met with Iranian foreign minister Javad Zarif.

He said: “We’re here for the UK to obviously stand with our European friends and partners, France and Germany to show our commitment to the deal.

“We think it has value even if America has decided to walk away, so we’ll be looking at a package of measures that we may be able to devise as Europeans, to encourage the Iranians to stay in the deal.”